1-Chloroethyl chloroformate → Ethyl 1-benzylpiperazine-2-carboxylate

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Reaction Steps

To a solution of ethyl 1,4-dibenzylpiperazine-2-carboxylate (6.76 g, 20 mmol) in 1,2-dichloroethane (20 mL) was added 1-chloroethyl carbonochloridate (3.15 g, 22 mmol) dropwise over a period of 30 minutes at 0° C., and the mixture was stirred at the temperature for another 15 minutes. Then the mixture was stirred at 90° C. for 1 hour. The mixture was concentrated in vacuo, and to the residue was added methanol (15 mL). The mixture was stirred at 70° C. for 1 hour and concentrated in vacuo. The residue was diluted with water and washed with DCM. The aqueous layer was adjusted to pH 9 with NaHCO3 aqueous solution and extracted with DCM. The organic layer was dried over Na2SO4, and concentrated in vacuo to give the title compound as yellow oil (3.06 g, 60%). The compound was characterized by the following spectroscopic data:

Provenance & Evidence